1. Technical Field
The present invention relates to a vehicle body manufacturing apparatuses that weld one work of a temporarily fixed vehicle body to another work to pre-assemble the vehicle body.
2. Related Art
There have been proposed and put into practical use various techniques for assembling a vehicle body by spot welding multiple works included in the vehicle body with the works positioned.
As a technique for assembling multiple types of vehicle body using this type of manufacturing apparatus, for instance, Japanese Published Examined Patent Application Publication (JP-B) No. 6-59851 discloses a technique that uses a vehicle body manufacturing apparatus to assemble multiple types of vehicle body having shapes at clamp positions of the vehicle body in common between vehicle body models, the vehicle body manufacturing apparatus including: multiple 3 axis switching units that each serve as a clamping device for positioning with a body side and a roof and that are suspension-supported and provided on both right and left sides of an upper frame of a vehicle body assembly station; and multiple 3 axis switching units that each serve as a clamping device for positioning with a body side and an under body and that are provided on both right and left sides of a lower frame of the vehicle body assembly station.
However, the clamping device disclosed in JP-B No. 6-59851 adopts the 3 axis switching units for positioning of a clamp jig, and thus some constraints are imposed. For example, shapes at clamp positions have to be provided in common between vehicle body models.
Although an articulated arm may be adopted for positioning of a clamp jig, it is difficult to position the clamp jig with high accuracy by simply adopting an articulated arm.